This invention relates to a protocol repeat/conversion system in particular, to a method and device of protocol repeat/conversion.
Conventional system of protocol repeat/conversion provides a mechanism that two terminal devices communicate each other via one virtual connection. An example of the conventional system is shown in RFC (request for comments) 1928.
In the protocol repeat/conversion system shown in RFC 1928, a protocol repeater/converter connected to each of two terminals repeats and converts transmitted data in the two connections, and then, the two terminals communicate each other.
In this system, the terminals recognize the two connections via the protocol repeater/converter as one virtual connection. To do so, a library for realizing API (application programming interface) is replaced to a library provided by the system. The provided library, namely a protocol repeat/conversion library, farther comprises functions for repeating and converting one protocol. The API of a communication application executed on the terminals is not modified. The protocol repeat/conversion library exchanges information to the protocol repeater/converter, and consequently, the system provides a framework for making two connections via the protocol repeater/converter look as one virtual connection by the terminals.
In the conventional protocol repeat/conversion system, only one type of protocol is supposed for exchanging information between the protocol repeater/converter and the protocol repeat/conversion library of the terminals. As a result, the protocol repeater/converter of the conventional system is unavailable for two terminals communicating by different protocols each other.
Further, the information transmitted between the conventional protocol repeater/converter and the terminals is not index information that directly indicates to the inner process for the receive terminal. As a result, the information exchanged by the conventional protocol repeater/converter should be converted again to the index information for the inner process. Consequently, the conventional protocol repeater/converter inefficiently converts information.
It is an object of this invention to provide a method, an apparatus and a recording medium for efficient protocol repeat/conversion.
It is another object of this invention to provide a method, an apparatus, and a recording medium for a protocol repeat/conversion to establish one virtual connection between two terminals. The terminals are operable in accordance with different protocols each other.
According to an aspect of this invention, it is provided that a method of communicating between a sending terminal and a receiving terminal via a protocol repeater/converter by establishing a virtual connection between the sending and the receiving terminals, the sending terminal being operable in accordance with a first protocol while the receiving terminal is operable in accordance with a second protocol different from the first protocol and has an receiver address according to the second protocol, comprising the steps of: (1) inputting to the sending terminal a logical host address name determined independently of the second protocol; (2) receiving, by the protocol repeater/converter, the logical host address name to generate an index for designating an receiver address defined in accordance with the second protocol: (3) recording, in the protocol repeater/converter, a relationship between the receiver address and the index; (4) sending the index back to the sending terminal from the protocol repeater/converter; (5) recording, by the sending terminal, the relationship; and (6) establishing, by the protocol repeater/converter, the virtual connection between the sending terminal and the receiving terminal with reference to the index.
In this method, each of the recording steps, (3) and (5) in the protocol/converter and the sending terminal may comprise the steps of: further recording the logical host address name together with the receiver address and the index as the relationship in the form of a table which has a plurality of lines; and designating one line of the table specified by the index. Further, The index may be represented by a selected one of a mathematically transformed value and a random number. And further, the recording step (5) in the sending terminal may comprise the steps of: preparing a socket API (application programming interface); generating, in the socket API, the logical host address name; preparing a protocol repeat/conversion library which includes the table; and recording the logical host address name in the table included in the protocol repeat/conversion library. In this case, the establishing step (6) comprises the steps of: preparing a protocol repeat/conversion program for accessing the table; and establishing the virtual connection with reference to the protocol repeat/conversion program.
According to another aspect of this invention, it is provided that a system for use in communicating between a sending terminal and a receiving terminal via a protocol repeater/converter by establishing a virtual connection between the sending and the receiving terminals, the sending terminal being operable in accordance with a first protocol while the receiving terminal is operable in accordance with a second protocol different from the first protocol and has an receiver address according to the second protocol, wherein: the sending terminal comprises: means for accepting a logical host address name independent of the second protocol; means for sending the logical host address name to the protocol repeater/converter; means for receiving an index related to the receiver address from the protocol repeater/converter; recording means for recording a relationship between the receiver address and the index; and means for sending the index for designating the receiver address to the protocol repeater/converter; the protocol repeater/converter comprising: means for receiving logical host address name from the sending terminal; means for resolving the receiver address from the logical host address name; means for generating the index related to the receiver address; recording means for recording the relationship between the receiver address and the index; means for sending the index back to the sending terminal; means for receiving the index from the sending terminal; and means for establishing the virtual connection between the sending terminal and the receiving terminal with reference to the relationship.
In this system, each of the recording means in the sending terminal and the protocol repeater/converter may comprise: means for recording the logical host address name together with the receiver address and the index as the relationship in the form of a table which has a plurality of lines; and means for designating one line of the table specified by the index. Further, the index is represented by a selected one of a mathematically transformed value and a random number. And further, the sending terminal may comprise: storage for a socket API (application programming interface); means for generating the logical host address name according to the socket API; storage for a protocol repeat/conversion library which includes the table; and means for recording the logical host address name in the table including in the protocol repeat/conversion library; the protocol repeater/converter comprising: storage for a protocol repeat/conversion program which accesses the table; and means for establishing the virtual connection according to the protocol repeat/conversion program.
According to another aspect of this invention, a sending terminal and a protocol repeater/converter below is provided. The sending terminal for use in communication to a receiving terminal via a protocol repeater/converter by establishing a virtual connection between the sending and the receiving terminals, the sending terminal being operable in accordance with a first protocol while the receiving terminal is operable in accordance with a second protocol different from the first protocol and has an receiver address according to the second protocol, comprises: means for accepting a logical host address name determined independently of the second protocol; means for sending the logical host address name to the protocol repeater/converter; means for receiving an index related to the receiver address from the protocol repeater/converter; means for recording a relationship between the receiver address and the index; and means for sending the index for designating the receiver address to the protocol repeater/converter. The protocol repeater/converter for use in communicating between a sending terminal and a receiving terminal via the protocol repeater/converter by establishing a virtual connection between the sending and the receiving terminals, the sending terminal being operable in accordance with a first protocol while the receiving terminal is operable in accordance with a second protocol different from the first protocol and has an receiver address according to the second protocol, comprises: means for receiving from the sending terminal a logical host address name generated by the sending terminal independent of the second protocol; means for resolving the receiver address from the logical host address name; means for generating an index related to the receiver address; means for recording the relationship between the receiver address and the index; means for sending the index back to the sending terminal; means for receiving the index from the sending terminal; and means for establishing the virtual connection between the sending terminal and the receiving terminal with reference to the relationship.
In this invention, concretely, information independent of a receiver protocol is exchanged in order to establish one virtual connection. With reference to the FIGS. 1 and 2, the sending terminal (1) comprises the protocol repeat/conversion library (13) which executes conversion process and exchanges information for the protocol repeater/converter (2) in order to establish one virtual connection for the communication application (15). The protocol repeater/converter (15) executes a protocol repeat/conversion program (24) which exchanges information for the protocol repeat/conversion library (13) and repeats/converts data streams through the two real connections. The protocol repeater/converter (15) also comprises sender and receiver protocol implementation (22, 23) each of which corresponds the protocol implementation 12 or 32. The protocol repeat/conversion library (13) and the protocol repeat/conversion program (24) exchanges each other their inner information in order to establish a virtual correction. To repeat and convert information between two terminals with different protocol implementations each other, this invention prepares address conversion table (132, 242) storing relationships of address information in the two connections. The address conversion tables (132, 242) further stores index numbers each of which indicates one relationship of address information. In this invention, two terminals operable in accordance with different protocols each other exchange the index number and consequently repeat/convert between two protocols.
To establish one virtual connection between a sending and receiving terminals via a protocol repeater/converter, the sending terminals and the protocol repeater/converter exchange their inner information. The sending terminal requests the protocol repeater/converter to resolve the address of the receiving terminal in the receiver protocol (receiver address) from a logical host address name determined independently of the receiver protocol. After resolving the receiver address, the protocol repeater/converter relates the receiver address to the logical host address name and stores their relationship with a index. After receiving the index, by sending the index to the protocol repeater/converter, the sending terminal communicates to the receiving terminal via the protocol repeat/converter with establishing a virtual connection.